Hi Darren,
I had a look at your site and the only issues i was able to notice off hand was the pathway not displaying properly and the shelf not closing (which looks like its attributed to a javascript conflict of sorts). Fixing the pathway is pretty simple and you can see my instructions on doing so here:
http://www.joomlajunkie.com/members...dated-absolute-flush.html
The shelf issue, i would just remove the option completely, as its pointless having it in there when its not working.
All that said, may i ask why you are wanting to move over to 1.5 when most of the components you are running require legacy mode turned on? Theres that old saying, if it aint broke, dont fix it

We see everyone jumping on the 1.5 bandwagon, when in all honesty its not actually ready for production. Yes it is now "officially" stable, but it is still the new kid on the block and has not being tested enough in a production environment. 1.0.x has years worth of solid testing and bug fixing and though its not perfect, i truly believe its the better option until 1.5 is tested more vigorously and all the major components are running natively.
I am working on a 1.5 site for my dad and i decided to go the 1.5 route because it was a new site and doesn't require anything more than a couple of content pages and contact form. If he needed some other functionality or components, i would probably have gone with 1.0.x instead..
Just my 5 cents though
Cheers,
Chris